HVAC Breaking News

Nov. 29, 2005: Additives May Improve Chiller Efficiency

November 29, 2005
/ Print / Reprints /
ShareMore
/ Text Size+
GAITHERSBURG, Md. - The National Institute of Standards and Technology (NIST) has announced that a researcher has come up with a method designed to improve the energy efficiency of commercial water chillers. The NIST method, if confirmed through experiments with full-scale chiller systems, could save as much as 1 percent of the 320 billion kWh of electricity used annually by chillers or an equivalent 5.5 million barrels of oil per year, according to Mark Kedzierski, the NIST mechanical engineer who developed the technique.

This advance builds on past NIST research designed to optimize mixtures of chiller refrigerants with lubricants. The researchers discovered that some lubricants, when injected in small amounts, can significantly enhance evaporator heat transfer, increasing the efficiency of chillers. When they studied the process more closely, they found the most efficient heat transfer occurred when the added oil's surface tension, viscosity, composition, and chemical characteristics complemented those of the chiller's base lubricant.

In a recent paper describing the method, Kedzierski describes how the right additive forms a very thin covering on an evaporator surface, which produces enhanced bubbling during boiling. The improved conversion of the refrigerant molecules into vapor molecules increases the chiller's cooling capacity similar to a heat pump.

Kedzierski developed rules for the selection of the different types of oil additives according to the type of chiller lubricant, making successful energy enhancement less of a hit-or-miss proposition. Laboratory work is under way testing the energy enhancing potential of several oil and lubricant combinations that have been identified by the rules.

"The leap from a successful laboratory experiment to an everyday large-scale cooling application is a big one. NIST wants to see this theory translated into products germane to manufacturers as soon as possible," Kedzierski said. "We welcome private-sector interest in the theory and its application."

Kedzierski can be contacted at mark.kedzierski@nist.gov or 301-975-5282.

Publication date: 11/28/2005

Did you enjoy this article? Click here to subscribe to The NEWS Magazine

You must login or register in order to post a comment.

Multimedia

Videos

Image Galleries

2014 MCAA Annual Convention

Scenes from the 2014 MCAA Annual Convention in Scottsdale, Ariz.

Podcasts

NEWSmakers: Julian Scadden

Training is an ongoing process. Julian will discuss how you can generate maximum return on time and energy invested training by following a three part process. Listen to this podcast to get expert tips on training, tracking and follow up. 

More Podcasts

ACHRNEWS

NEWS 04-21-14 cover

2014 April 21

Check out the weekly edition of The NEWS today!

Table Of Contents Subscribe

SERVICE CALLS POLL

Which statement on service calls best applies to your business?
View Results Poll Archive

HVACR INDUSTRY STORE

plumbing-hvac.gif
2014 National Plumbing & HVAC Estimator

Every plumbing and HVAC estimator can use the cost estimates in this practical manual!

More Products

Clear Seas Research

 

Clear Seas ResearchWith access to over one million professionals and more than 60 industry-specific publications, Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.

DON'T MISS A THING

Magazine image
 
Register today for complete access to ACHRNews.com. Get full access to the latest features, Extra Edition, and more.

STAY CONNECTED

facebook icontwitter iconyoutube iconLinkedIn i con